You need to keep the physical address associated with your SIP trunk phone number current for emergency services. That way, if 911 is called from the phone, first responders will know what address to go to. Emergency services will only be routed to the address listed on the My 911 Locations screen. In addition to the address, the first name, last name, and email address must also be assigned to the user. This is known as a primary place of use (PPU).